Personal wash compositions seek to provide consumers with additional skin benefits beyond simple cleansing. One of the principle benefits provided by such compositions is moisturization. Among the many moisturization benefit agents the most commonly used agents for good moisturization are emollient oils such as triglyceride based oils (e.g. vegetable oils) and petroleum based hydrocarbon oils (e.g., mineral oil or petroleum jelly, also known as petrolatum). These emollients are commonly used for their low cost or good occlusive power.
Emollients such as petrolatum and liquid triglycerides can be easily spread and pressed down onto skin to form a thin, hydrophobic film that can retard skin dehydration and alleviate the irritation or lipid/protein damage from surfactants. The emollient oils play this role in body wash products only when a sufficient amount of the emollient can be deposited and retained after rinsing. In this sense, viscous, semi-solid gels (e.g., petroleum) are typically more efficient than liquid triglyceride oils since, because of their rheology, they are more readily deposited and more difficult to rinse off. On the other hand, triglyceride vegetable oils are natural botanics which have milder properties and are less greasy feeling than petroleum sourced oils.
It would thus be desirable to find a triglyceride vegetable oil blend which could be readily pressed down and deposited onto skin (e.g., has rheological characteristics similar to) as easily as petroleum based oil. One way of accomplishing this is to use solid particles or high melting wax to thicken vegetable oil so that it has rheological properties similar to that of, for example, petrolatum. The problem is that the high crystallinity material in structured oils usually also produces lessened foam values, as compared to the similar formulations without high melting material structured oils.
Unexpectedly, applicants have now discovered that, if a specific ratio of fully hydrogenated and non-hydrogenated vegetable oils is used (e.g., in the case of soybean oil, such that iodine number of mixture is above 70, preferably above 80, preferably 81 to about 120), it is possible to simultaneously produce an emollient which has a rheology similar to that of petrolatum (and should deposit more readily), while also maintaining a foam value which is not depressed relative to use of the unsaturated triglyceride oil alone for a perceivable period of time (e.g., has foam value at least 70% as great as unsaturated triglyceride vegetable oil alone when foam value of otherwise identical liquid composition in which triglycerides are used is measured).
More specifically, to enhance the deposition effectiveness of the occlusive oils while still retaining the substantial lather volume generated by foaming surfactants, regular vegetable oils (unsaturated triglyceride oils) are in effect thickened by simply blending those regular triglyceride oils with their corresponding fully hydrogenated oils at the optimal weight ratios. Non-limiting examples of the partially saturated triglyceride oils which can be structured or thickened while retaining good foam using optimal blends of the invention include sunflower oil, castor oil, coconut oil, cottonseed oil, menhaden oil, palm kernel oil, palm oil, peanut oil, soybean oil, rapeseed oil, linseed oil, rice bran oil, pine oil, sesame oil, rice bran oil, all their corresponding hydrogenated counterparts and mixtures thereof.
EP 1,479,365 discloses benefit agent materials structured with crystalline material. U.S. Publication 2004/023569 A1 discloses non-bar compositions comprising crystalline wax structured benefit agent. U.S. 2004/0234467 A1 discloses compositions comprising structured benefit agent for deposition of hydrophilic benefit agent. EP 1,479,378 relates to bars with crystalline wax structured delivery vehicle.
U.S. 2004/0234468, U.S. 2004/0234469 and U.S. 2004/0234558 disclose structured premix to enhance delivery of hydrophobic agent.
WO 2004/017745 discloses mixing non-hydrogenated and hydrogenated oils for dispersed liquid oil or solid particles in fat phase for food compositions.
None of these references disclose specific blends of fully saturated to unsaturated triglycerides which must be within specifically defined ratios to achieve optimum rheology (e.g., for deposition).
U.S. 2005/0281851 to Cap discloses cosmetic products comprising vegetable oil blends and additional fatty acid where blends have iodine value range of 20-80 and no applicable viscosity range specified. There is no disclosure of the critical ratios of the invention. Further, in at least one emollient of the present invention (e.g., for soybean oil blends) the compositions, include triglyceride oil blends with higher iodine value, specifically an iodine value from 81 to 120 that will give the desired oil viscosity (for deposition). Such blend should have viscosity superior for deposition and maintain good foam compared to the vegetable oil blends with iodine value range of 20-80 in Cap reference. Also, as noted, there is no criticality to ratio of blends in Cap.